Jon Spangler
Writer/editor
Linda Hudson Writing
TEL 510-864-2144
CEL 510-846-5356
JonSwriter@att.net
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Dear All,
If brake cables are not stretching when new (and requiring re-attachment to take up the slack), what is it that is causing this need for readjustment after installing any new brake cables?
I am all ears (and eyes), folks....
Jon Spangler Curious in Alameda, CA USA and still at a late-night City Council meeting
Message: 13 Date: Tue, 4 Jan 2011 22:10:44 -0800 From: "paccoastcycles" <paccoastcycles@sbcglobal.net> Subject: Re: [CR] Brakes and flex To: "Ken Freeman" <kenfreeman096@gmail.com>, "John Betmanis" <johnb@oxford.net> Cc: classicrendezvous@bikelist.org Message-ID: <280940BA0D074C1EBE759E250580C329@ownerd556865ac> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original
John Betamus, thank you for making me not feel alone in the world of bicycle mechanics with regard to cables not stretching. I'm always shagrined (not crestfallen) when I hear someone who says their mechanic said this or that about cable stretch. I think of it this way: If you try to hang a car from a bridge with a bicycle cable, it will stretch...and then break. But the forces we put on these cables are not stretching them.
Chuck Hoefer
Pacific Coast Cycles
Oceanside, Ca.
> I've made a lot of improvement in the feel of previously bad brakes by
> replacing with modern inner and outer cables, carefully terminated by
> filing
> and with ferrules.
>
> On Tue, Jan 4, 2011 at 4:42 PM, John Betmanis <johnb@oxford.net> wrote:
>
>> On 04/01/2011 3:53 PM, Harry Travis wrote:
>>
>> Please someone, show me that new design stainless steel cables stretch
>>> less
>>> than old-skool zinc-plated ones (any more than bicycle chains
>>> "stretch.")
>>> Which is to say: Show me that they measurably stretch at all, as against
>>> simply having the ends bed and the housings move.
>>>
>>
>> Springiness or lost motion in brake cables is no more due to "stretch"
>> than
>> a worn-out chain is "stretched". It's the housing that's the culprit when
>> it
>> appears to "compress". If there is excessive clearance between the inner
>> cable and the housing, the housing will "buckle" in a series of "S"
>> curves
>> before any serious tension reaches the brake caliper. Moreover, if the
>> housing is made of round section wire rather than rectangular, the coils
>> can
>> also "slip" allowing more "compression". I believe the reason the better
>> modern cables have less "stretch" is due to better design and closer
>> tolerances.
>>
>> --
>> John Betmanis
>> Woodstock, Ontario
>> Canada